The invention relates to a generic wire-hook connector including side by side wire hooks that are held on a carrier material and which serve as a belt connector for connecting ends of adjacent belts ends one to the other, and to a conveyor or belt provided therewith, forming a conveyor splice.
Such mechanical wire-hook connectors in which the carrier material comprises paper are known as “carded” connectors. The individual wire hooks in such wire-hook connectors have hook legs that are pre-bent into a V-shape and that have different lengths. Hook tips that run toward one another are disposed on both hook leg ends and are pressed by means of suitable apparatus and machines into the end of, for example, a transport conveyor, hereinafter also called a conveyor, or conveyor belt, hereinafter also called a belt, connecting another end of a conveyor, in that the projecting wire hooks from one end of the other conveyor are inserted into the gaps between the wire hooks of the other end of the conveyor and a hinge pin is inserted through the through-opening thus formed.
These known, in particular, carded, wire-hook connectors have proved themselves to best advantage especially when used in the laundry industry and in conveyor filters because, after a few weeks of run-time, the conveyor splice, due to very different loads over the entire conveyor width, is seldom flat, but rather, is frequently wavy.
In the known carded wire-hook connectors, the carrier material, made of paper, assumes a spacer function for the individual wire hooks until they are installed. The carrier material also guides the wire hooks during the pressing process, so that the latter are all bent uniformly in one direction. After the pressing process, the paper in the strip is no longer needed, in fact is interfering, and must be removed. Depending on the conveyor or belt thickness, length of the hook tips, and pressure used, this can be very time-intensive during installation, because the hook tips pass through the paper and clamp it tightly.
In practice, conveyors in the laundry industry, filter conveyors, and corrugated board belts are frequently pre-treated in the connection area, i.e., different stabilization processes are used in the area of the conveyor splice so that the wire-hook connectors have a better grip or can be installed with high pressure. Furthermore, this type of pre-treatment also helps to ensure that the wire-hook connectors do not pull apart under the tensile load of the conveyor.
In many cases the wire-hook connectors are covered in another work step. This protects the wire-hook connectors against wear and also protects the items being conveyed against damage from any projecting, pointed parts of the individual wire hooks.
The pre-treatment of the belt, which is somewhat elastic in the longitudinal direction, is performed, for example, in the laundry industry, by dipping the two ends of the belt into clear varnish or adhesive and then drying, sometimes for several hours, until the varnish or adhesive has cured and during installation does not stick to the machine or equipment. Alternatively, patches are adhesively applied using a thermotransfer method or are placed around the conveyor ends and sewn thereto. All of the methods used in the past require several work steps and are time-consuming. All of the measures used heretofore are ultimately intended to protect the conveyor from fraying. These known methods do not protect the items being conveyed from damage, for example, terrycloth towels in the laundry industry. Another suggested solution for protecting the items being conveyed is embodied in wire-hook connectors having individual wire hooks which are connected to a crosswire, sometimes referred to as crosswire connectors (see, for example, EP 1 338 825 A).
In the conveyor filter industry, the connection area is densified, for example, with two-component adhesives prior to installation. In this case, as well, the drying time for the adhesive until the wire-hook connectors can finally be installed is crucial to production, not only because of the storage space required, but other considerations as well.
Finally, in the corrugated board industry, the conveyors are pre-densified, sometimes with the addition of heat to 200° C. Then, the wire-hook connectors are installed. Afterwards, they are sometimes coated in order to prevent a damaging antistatic charge during the production process and to reduce the wear on the wire-hook connector.
In other industrial fields, the wire-hook connectors are “let in” to the conveyor. This is done for instance by heating the wire-hook connectors during or after installation, and also by removing the conveyor covers on the conveyor top side and/or conveyor bottom side, and then re-vulcanizing the removed cover after installing the wire-hook connectors.
The aforementioned crosswire hooks, i.e., individual wire hooks that are held together by virtue of being, for example, welded to a crosswire, and that therefore do not require any paper as a carrier material, have been known for a number of years. Use of such wire-hook connectors in the above-mentioned industries and the conveyors and belts used in them is limited, however. It sometimes happens, that due to, for example, cambered roll rattle, the crosswire breaks and projecting wire parts, despite being covered, damage the items being conveyed. Moreover, the risk of injury to the operators of the machine from small projecting wire parts cannot be overlooked. Due to the conveyor splices not running parallel, sometimes the crosswire breaks in filter conveyors and corrugated board belts, resulting in residual pieces sometimes traveling into the filtered material. In order to minimize this risk, for this known wire-hook connector, an additional cover element is placed over the series of wire hooks during production or prior to installation and after installation it fulfills a cover function, in particular for the crosswire (see, for example, EP 1 338 825 A).
The underlying object of the invention is to create a generic wire-hook connector in a manner that is simpler and less complex to install.